This is a pretty religious topic, but as a Catholic, I’m taught that people can be forgiven by God no matter how bad their sins are if they choose to repent and try and find redemption. Arthur has done a lot of bad things, but as we see in his high honor run (which I believe to be the canon run), he tried his best to do good. He did kill a lot of people, but he didn’t do it in cold blood. I’d hope he’d have a chance.